Note
Go to the end to download the full example code.
Ship drift
from datetime import datetime
from opendrift.models.shipdrift import ShipDrift
o = ShipDrift(loglevel=20)
o.add_readers_from_list([
'https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml',
'https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc',
'https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml'
])
08:26:26 INFO opendrift:568: OpenDriftSimulation initialised (version 1.14.9 / v1.14.9-9-gcde0dcf)
Seed ship elements at defined position and time Note: beam/length ratio is larger than allowed, but is then clipped internally
o.seed_elements(lon=5.0, lat=63.0, radius=1000, number=1000,
time=datetime.now(),
length=80.0, beam=20.0, height=9.0, draft=4.0)
08:26:26 WARNING opendrift.models.shipdrift:180: Ratio of beam to length should be in range 0.12 to 0.18, given range is 0.25-0.25. Using border value.
08:26:26 INFO opendrift.models.basemodel.environment:203: Adding a global landmask from GSHHG
08:26:30 INFO opendrift.models.basemodel.environment:227: Fallback values will be used for the following variables which have no readers:
08:26:30 INFO opendrift.models.basemodel.environment:230: horizontal_diffusivity: 100.000000
08:26:30 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_stokes_drift_x_velocity: 0.000000
08:26:30 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_stokes_drift_y_velocity: 0.000000
08:26:30 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_significant_height: 0.000000
08:26:30 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment: 0.000000
Running model
o.run(steps=24, stop_on_error=True)
08:26:30 INFO opendrift:1839: Storing previous values of element property lon because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
08:26:30 INFO opendrift:1839: Storing previous values of element property lat because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
08:26:30 INFO opendrift:947: Using existing reader for land_binary_mask to move elements to ocean
08:26:30 INFO opendrift:978: All points are in ocean
08:26:30 INFO opendrift:2136: 2026-03-25 08:26:26.272919 - step 1 of 24 - 1000 active elements (0 deactivated)
08:26:30 INFO opendrift.readers:64: Opening file with xr.open_dataset
08:26:32 INFO opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'x': 'x', 'y': 'y', 'time': 'time'}
08:26:32 INFO opendrift.readers:64: Opening file with xr.open_dataset
08:26:33 INFO opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'time': 'time', 'x': 'x', 'y': 'y'}
08:26:33 INFO opendrift.readers:64: Opening file with xr.open_dataset
08:26:35 INFO opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'y': 'rlat', 'x': 'rlon', 'time': 'time'}
08:26:37 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:37 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:37 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:37 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:39 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:26:39 INFO opendrift:2136: 2026-03-25 09:26:26.272919 - step 2 of 24 - 1000 active elements (0 deactivated)
08:26:40 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:40 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:41 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:26:41 INFO opendrift:2136: 2026-03-25 10:26:26.272919 - step 3 of 24 - 1000 active elements (0 deactivated)
08:26:42 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:42 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:42 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:26:42 INFO opendrift:2136: 2026-03-25 11:26:26.272919 - step 4 of 24 - 1000 active elements (0 deactivated)
08:26:43 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:43 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:44 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:26:44 INFO opendrift:2136: 2026-03-25 12:26:26.272919 - step 5 of 24 - 1000 active elements (0 deactivated)
08:26:45 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:45 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:46 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:26:46 INFO opendrift:2136: 2026-03-25 13:26:26.272919 - step 6 of 24 - 1000 active elements (0 deactivated)
08:26:48 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:48 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:49 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:26:49 INFO opendrift:2136: 2026-03-25 14:26:26.272919 - step 7 of 24 - 1000 active elements (0 deactivated)
08:26:51 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:51 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:51 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:26:51 INFO opendrift:2136: 2026-03-25 15:26:26.272919 - step 8 of 24 - 1000 active elements (0 deactivated)
08:26:53 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:53 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:53 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:26:53 INFO opendrift:2136: 2026-03-25 16:26:26.272919 - step 9 of 24 - 1000 active elements (0 deactivated)
08:26:56 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:56 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:56 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:26:56 INFO opendrift:2136: 2026-03-25 17:26:26.272919 - step 10 of 24 - 1000 active elements (0 deactivated)
08:26:59 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:26:59 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:00 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:27:00 INFO opendrift:2136: 2026-03-25 18:26:26.272919 - step 11 of 24 - 1000 active elements (0 deactivated)
08:27:02 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:02 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:02 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:27:02 INFO opendrift:2136: 2026-03-25 19:26:26.272919 - step 12 of 24 - 1000 active elements (0 deactivated)
08:27:05 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:05 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:05 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:27:05 INFO opendrift:2136: 2026-03-25 20:26:26.272919 - step 13 of 24 - 1000 active elements (0 deactivated)
08:27:08 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:08 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:08 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:27:08 INFO opendrift:2136: 2026-03-25 21:26:26.272919 - step 14 of 24 - 1000 active elements (0 deactivated)
08:27:10 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:10 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:11 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:27:11 INFO opendrift:2136: 2026-03-25 22:26:26.272919 - step 15 of 24 - 1000 active elements (0 deactivated)
08:27:12 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:12 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:13 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:27:13 INFO opendrift:2136: 2026-03-25 23:26:26.272919 - step 16 of 24 - 1000 active elements (0 deactivated)
08:27:15 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:15 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:17 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:27:17 INFO opendrift:2136: 2026-03-26 00:26:26.272919 - step 17 of 24 - 1000 active elements (0 deactivated)
08:27:18 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:18 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:19 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:27:19 INFO opendrift:2136: 2026-03-26 01:26:26.272919 - step 18 of 24 - 1000 active elements (0 deactivated)
08:27:21 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:21 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:21 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:27:21 INFO opendrift:2136: 2026-03-26 02:26:26.272919 - step 19 of 24 - 1000 active elements (0 deactivated)
08:27:23 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:23 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:24 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:27:24 INFO opendrift:2136: 2026-03-26 03:26:26.272919 - step 20 of 24 - 1000 active elements (0 deactivated)
08:27:25 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:25 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:26 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:27:26 INFO opendrift:2136: 2026-03-26 04:26:26.272919 - step 21 of 24 - 1000 active elements (0 deactivated)
08:27:28 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:28 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:29 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:27:29 INFO opendrift:2136: 2026-03-26 05:26:26.272919 - step 22 of 24 - 1000 active elements (0 deactivated)
08:27:30 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:30 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:31 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:27:31 INFO opendrift:2136: 2026-03-26 06:26:26.272919 - step 23 of 24 - 1000 active elements (0 deactivated)
08:27:33 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:33 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:35 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
08:27:35 INFO opendrift:2136: 2026-03-26 07:26:26.272919 - step 24 of 24 - 1000 active elements (0 deactivated)
08:27:37 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:37 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
08:27:39 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
Print and plot results
print(o)
o.plot(linecolor='orientation')
#o.animation(color='orientation', markersize=20, filename="orientation.gif", legend=['left','right'],colorbar=False,cmap='bwr')
o.animation(color='orientation', legend=['left','right'], markersize=20, colorbar=False, cmap='bwr')

===========================
--------------------
Reader performance:
--------------------
global_landmask
0:00:01.7 total
0:00:00.0 preparing
0:00:01.7 reading
0:00:00.0 masking
--------------------
https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml
0:00:16.9 total
0:00:00.0 preparing
0:00:16.9 reading
0:00:00.0 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc
0:00:25.4 total
0:00:00.0 preparing
0:00:25.3 reading
0:00:00.2 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml
0:00:19.7 total
0:00:00.0 preparing
0:00:19.6 reading
0:00:00.0 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
Performance:
1:14.8 total time
4.2 configuration
0.0 preparing main loop
0.0 moving elements to ocean
1:08.8 main loop
0.4 updating elements
1.7 cleaning up
--------------------
===========================
Model: ShipDrift (OpenDrift version 1.14.9)
1000 active ShipObject particles (0 deactivated, 0 scheduled)
-------------------
Environment variables:
-----
land_binary_mask
1) global_landmask
-----
x_sea_water_velocity
y_sea_water_velocity
1) https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml
2) https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml
-----
x_wind
y_wind
1) https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc
-----
sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment
sea_surface_wave_significant_height
sea_surface_wave_stokes_drift_x_velocity
sea_surface_wave_stokes_drift_y_velocity
1) https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml
-----
Readers not added for the following variables:
horizontal_diffusivity
Discarded readers:
Time:
Start: 2026-03-25 08:26:26.272919 UTC
Present: 2026-03-26 08:26:26.272919 UTC
Calculation steps: 24 * 1:00:00 - total time: 1 day, 0:00:00
Output steps: 25 * 1:00:00
===========================
08:28:10 INFO opendrift:4697: Saving animation to /root/project/docs/source/gallery/animations/example_shipdrift_0.gif...
08:28:29 INFO opendrift:3120: Time to make animation: 0:00:20.533835
Total running time of the script: (2 minutes 11.328 seconds)